PORTSMOUTH, a city and the county-seat of Scioto county, Ohio, U.S.A., picturesquely situated at the confluence of the Scioto and Ohio rivers, 95 m. S. of Columbus. Pop. (1910 U.S. census) 23,481. Portsmouth is served by the Baltimore & Ohio South-Western, the Chesapeake & Ohio and the Norfolk & Western railways, also by passenger and freight boats to Pittsburg, Cincinnati and intermediate ports. The city has a Carnegie library, a municipal hospital, an aged women's home and a children's home. Extending along the Ohio for 8 m. and arranged in three groups are works of the “Mound Builders.” There are two small city parks, and a privately owned resort, Millbrook Park. The surrounding country is a fine farming region, which also abounds in coal, fire-clay and building stone. Natural gas is used for light, heat and power. In 1905 the city's factory products were valued at $7,970,674, of which $4,258,855 was the value of boots and shoes. The Norfolk & Western has division terminals here.

The first permanent settlement in the immediate vicinity was made in 1796. In 1799 Thomas Parker, of Alexandria, Virginia, laid out a village (which was named Alexandria) below the mouth of the Scioto, but as the ground was frequently Hooded the village did not thrive, and about 1810 the inhabitants removed to Portsmouth. Portsmouth was laid out in 1803, incorporated as a town in 1815, and chartered as a city in 1851. The Ohio and Erie canal was opened from Cleveland to Portsmouth in 1832.